Research On Autonomous Navigation Technology Of Indoor Mobile Robot Based On Ultrasonic Ranging

With the development of science and technology and the improvement of people's living standard,indoor mobile robot has made rapid development and wide application.Autonomous Navigation Technology of indoor mobile robots is the most basic and important technology of robot,it is also a prerequisite for other intelligent tasks.In order to realize the popularization of indoor mobile robot,it is of great significance to study a high precision and low cost robot navi gation system.Compared with other sensors,ultrasonic sensor has the advantages of high positioning accuracy and low cost,and also has the shortcomings of small positioning range.Therefore,this study has studied the method of high precision positioning with ultrasonic sensor in a large scale.Based on this,the path planning algorithm is studied,and the autonomous navigation of indoor mobile robot is realized.Firstly,the basic principle of ultrasonic positioning system is analyzed.In view of the small range of ultrasonic positioning and the disadvantage of being unable to locate when shielded,we used a combined positioning mode of ultrasonic positioning and dead reckoning.And we use surround ultrasonic module and dynamic optimization algorithm to enlarge its range.The location principle and error of the dynamic optimization algorithm are analyzed.We set up a dual extended Kalman filter model and merge the dead reckoning data and improvement of ultrasonic positioning data to obtain the optimal pose.Through MATLAB simulation,it is proved that the localization range of the robot is greatly expanded under the premise of guaranteeing the positioning accuracy.Secondly,we use grid method to describe maps and propose a combination of global path planning based on improved A-star algorithm and fuzzy control path planning.In the matlab environment,the A * algorithm and the improved A * algorithm are compared and verified.The results show that the number of turnarounds of the improved A * algorithm is reduced and the efficiency of the improved A * algorithm is improved obviously,which is beneficial to the real-time control of mobile robot navigation.The local path planning system based on fuzzy control is established,and the feasibility of local obst acle avoidance of mobile robot is verified by simulation.Finally,the simulation based on improved A * and fuzzy control path planning is carried out.The results show that the algorithm can efficiently plan a smoother path and realize the local obstacle avoidance of mobile robot.Thirdly,we completed the construction of the hardware part of the mobile robot and programmed it.The hardware part includes the hardware construction of the ultrasonic positioning system,the hardware construction of the ultra sonic obstacle avoidance system.The software part includes the launch controller and the receiver controller program design,based on the lower computer sensor reading and the motor control program design,finally completes the navigation system master program design.Finally,we verify the localization and navigation algorithms through experiments.It includes indoor mobile robot localization experiments and robot navigation experiments in different environments.The results show that the localization accuracy of this algorithm is less than 10 cm,which can meet the requirements of indoor positioning,and can realize real-time navigation and local obstacle avoidance for the robot.